This winter I swapped out the Muncie M21 for the TKO 600. I wanted the tall gearing of the 0.64 because the current engine was built for torque down low, 516 lb/ft @ 2800, this pushing a car that weighs 1790 lbs. The picture says I'm geared tall enough for my taste. Last 1200 mile roundtrip netted 24.6, 30.2, 15.9, 28.2 mpg.
